Today’s Wonder of the Day was inspired by Jason from Etiwanda, CA. *Jason Wonders*, “**Is it possible to fold a paper 7 times?**” Thanks for WONDERing with us, Jason!

With modern technology and digital devices being so prevalent in our lives today, many people have suggested that one day paper will become a thing of the past. After all, you can now read books and newspapers on a digital device. Adults can pay for things with debit or credit cards and can conduct business online, too, like pay bills electronically.

Paper isn't dead yet, though. Bookstores still stock paper books on their shelves. Newspapers still print daily editions, and magazines still line the shelves of many stores. Paper also remains a popular medium for various fun projects, from making paper airplanes to folding paper into origami objects and animals.

Speaking of folding paper, have you ever heard that it's impossible to fold a piece of paper more than 7 times? This is a popular myth that gets repeated on a regular basis when people talk about folding paper. Unlike many myths, though, this one has a mathematical and scientific basis to it.

If you've ever created works of paper art via origami, then you might find this paper-folding myth quite curious. After all, most origami works of art involve folding pieces of paper dozens or even hundreds of times.

The paper-folding myth refers to folding a piece of paper in half multiple times in any direction. Try it for yourself with a regular piece of notebook paper. The first couple of folds are easy. As you approach the fifth and sixth folds, though, you'll notice that it's increasingly harder to fold the now compact piece of paper.

It's not uncommon for many kids only to be able to fold a piece of paper six times. If you have strong hands and help from a friend, you may be able to achieve that elusive seventh fold. More than seven folds, though, would seem to be impossible, thus giving rise to the popular myth that seven folds is all that's possible.

The folding limitation of paper is caused by a couple of factors. First, there's the problem of exponential growth: the number of layers of paper doubles with each fold. For example, after the sixth fold, you're left with 64 layers of paper rather than the single layer you started with. It's easy to see why it's harder to fold 64 layers of paper than just one!

The other problem you encounter has to do with the paper itself. When folded multiple times, the paper gets much smaller, especially compared to its increasing thickness. The paper also gets distorted as its creases become more rounded with each fold. Eventually, the paper fibers themselves aren't flexible enough to allow further folds.

At this point, you may be thinking that the paper-folding myth doesn't sound much like a myth at all. That's what many people thought until a high school student named Britney Gallivan proved everyone wrong back in 2002.

Britney successfully folded a 4,000-foot-long roll of toilet paper an unheard-of 12 times! As if that wasn't impressive enough, she also developed a mathematical theorem that allows you to calculate the maximum number of folds possible based upon factors such as paper thickness, paper length, and direction of folding.

As you can see, paper can be folded more than seven times. You just need to use bigger and bigger pieces of paper to increase the number of folds possible. It can be fun to play with the mathematics of paper folding to see how thickness increases exponentially with each fold.

For example, if you start with an average piece of paper that's 1/10^{th} of a millimeter thick (0.0039 inches), it'll be as thick as a notebook after seven folds. If you could keep folding it, at 23 folds it would be one kilometer (3,280 feet) thick! At 42 folds, it would extend to the Moon and, finally, at a whopping 103 folds, that piece of paper would exceed the size of the observable universe at over 93 billion light-years in diameter!